Improved vascular engraftment and graft function after inhibition of the angiostatic factor thrombospondin-1 in mouse pancreatic islets
2008 (English)In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 57, no 7, 1870-1877 p.Article in journal (Refereed) Published
OBJECTIVE: Insufficient development of a new intra-islet capillary network after transplantation may be one contributing factor to the failure of islet grafts in clinical transplantation. The present study tested the hypothesis that the angiostatic factor thrombospondin-1 (TSP-1), which is normally present in islets, restricts intra-islet vascular expansion posttransplantation. RESEARCH DESIGN AND METHODS: Pancreatic islets of TSP-1-deficient (TSP-1(-/-)) mice or wild-type islets transfected with siRNA for TSP-1 were transplanted beneath the renal capsule of syngeneic or immunocompromised recipient mice. RESULTS: Both genetically TSP-1(-/-) islets and TSP-1 siRNA-transfected islet cells demonstrated an increased vascular density when compared with control islets 1 month after transplantation. This was also reflected in a markedly increased blood perfusion and oxygenation of the grafts. The functional importance of the improved vascular engraftment was analyzed by comparing glucose-stimulated insulin release from islet cells transfected with either TSP-1 siRNA or scramble siRNA before implantation. These experiments showed that the increased revascularization of grafts composed of TSP-1 siRNA-transfected islet cells correlated to increments in both their first and second phase of glucose-stimulated insulin secretion. CONCLUSIONS: Our findings demonstrate that inhibition of TSP-1 in islets intended for transplantation may be a feasible strategy to improve islet graft revascularization and function.
Place, publisher, year, edition, pages
2008. Vol. 57, no 7, 1870-1877 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-100537DOI: 10.2337/db07-0724ISI: 000257420000016PubMedID: 18420490OAI: oai:DiVA.org:uu-100537DiVA: diva2:210470